#include<stdio.h>
#include<unistd.h>
int main()
{
while(1)
{
 printf("I am runing ....\n");
 int id = fork();
 if(id==0)
 {
   while(1)
   {
     printf("do something\n");
     sleep(1);
   }
 }

 else if(id>0)
 {
while(1)
{
  printf("call child,do something!\n");
  sleep(2);
}

 }

else
{

}
}

return 0;
}
